AHTN (6-Acetyl-1,1,2,4,4,7-hexamethyltetraline) is a member of a group of substances used in fragrances and known collectively as the polycyclic musks. It is used to make a fragrance long lasting and to have a positive technical effect on its balance bringing the initial and residual smell into harmony.
AHTN is produced in one plant in The Netherlands in an annual volume of 1000 to 5000 tonnes.
It is used as an ingredient in commercial preparations intended to be used as fragrances in a wide variety of consumer products such as perfumes, cosmetics, household and laundry cleaning products and air fresheners. These commercial preparations are not sold retail. The level of AHTN in such preparations is typically at a level of several percent. The principal exposure to AHTN from household products can be considered to be via the skin.
The relative volume of use in household products versus perfumes, cosmetics, etc. is not known although the majority can be assumed to be used in household products based on the relative volume of sales of such products.
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The oral LD50 values for AHTN ranged from 570-1377 mg/kg bw. The dermal LD50-values are >5000 mg/kg bw. Inhalation exposure has been estimated to be negligible relative to dermal.
AHTN is not a skin or eye irritant and shows no phototoxicity potential on humans at concentrations significantly higher than would be encountered from the use of fragranced household products. There is no significant evidence either from animal or human studies of potential for dermal sensitisation. AHTN shows no photosensitisation potential on humans at concentrations significantly higher than would be encountered from the use of fragranced consumer products.
In a 90-day oral study, a NOAEL of 5 mg/kg bw/day for AHTN in rats can be concluded.
There were no indications of effects on fertility or the developing foetus up to and including 50 mg/kg bw/day, the highest dose tested.
There were no effects on rat pups exposed via the milk during nursing to levels of AHTN over 1000 times the maximum level found in human milk samples.
AHTN is a non-genotoxic substance. The mutagenicity data and the repeated dose studies with AHTN do not indicate a concern with regard to carcinogenicity nor does AHTN possess any structural features that would raise a concern.
In the unlikely event of maximum exposures from direct and indirect skin contact as well as from the oral route via dishware residues, the estimated total exposure to AHTN from its use in household cleaning products is 0.033 µg/kg bw/day. Comparison of this exposure to the NOAEL results in a calculated margin of safety of at least 75,000 and indicates that there is no significant risk to human health from exposure to AHTN as used in household cleaning products.